Plz help I'm lagging out every game

So I've been playing league for awhile and I've never really had any issues with lag out side ofy internet disconnected and after I got a new router I never lagged but now every game at the 9 to 10 minute mark my game lags out for like 2 to 3 min and then replaces me at base and saying g attempting to reconnect and when I do I'm back to level 1 with no items then back to the level I was at then when I trying to buy items it does not buy for me and puts me back to level 1 I've been having this problem for like 5 games and I need help